This holiday season, the Evanston Symphony Orchestra hosted a new kind of concert. The so-called “barrier-free” performance was designed for people with disabilities and their loved ones. That includes accessible parking, an ASL interpreter and a sensory-free room where people could retreat if they got overwhelmed. About a hundred attendees of all ages poured into the performance at the Evanston Township High School Auditorium, where volunteers encouraged the audience to participate in a singalong performance and shake jingle bells.